Sound picture set



June

SOUND PICTURE SET Filed Dec. 15, 1933 V F. L. HUNT 2 Sheets-Sheet 1 AINVENTOR F. L. HUNT ATTORNEY June 4, 1935. L, N 2,003,937

SOUND PICTURE SET File'd Dec. 15, 1935 2 Sheets-Sheet 2 a Q F/G.' 2 V f4/ v /6 f 4 g 2o /9' /7 2 ,9 b

I F i 1 I i i 22 g 7 /ai i '/a 5 g l l l i g 5 i g IN VE N TOR l-'. L.HUNT 8V ATTORNEY Patented June 4, 1935 UNITED STATES PATENT OFFICE SOUNDPICTURE SET Application December 15, 1933, Serial No. 702,448

Claims.

This invention relates to studios for sound recording and particularlyto sound picture sets.

An object of the invention is to improve the acoustics of sound picturesets for recording.

Heretofore it has been the custom in taking sound pictures in a studioto set up a temporary structure comprising two or three walls havinghighly reflecting surfaces to simulate the walls of a room or otherscenic effects and to form a semi-enclosure for the performer. Althoughthe quality of sound production in such an arrangement may be judged tobe good by a person listening directly to it, there is sometimes ahollowness of tone in the reproduction from a record made with one ortwo transmitters and recorded by a single recorder. The reason for thisis that with two or three reflecting walls there is a wide variation inrelative intensity with frequency at the microphone position and these20 variations appear in the record. When one listens directly, thesevariations do not occur simultaneously at both ears, and ones binauralsense compensates for this uneven distribution and variation inintensity of sound energy.

One of the features of this invention therefore is to minimize this sortof distortion by controlling the acoustics of sound picture sets so thatthe sound intensity at any point is more nearly uniform with frequency.

In one embodiment the invention provides a sound picture set in asubstantially dead sound studio, the set having highly reflecting wallssubstantially enclosing the performers leaving an opening in one sidewall only of sufficient size through which to operate a motion picturecamera and before which the microphone is preferably supported.

Referring to the drawings which shown but one embodiment of theinvention:

Fig. l is a plan view of a sound picture studio embodying the invention;

Fig. 2 is a sectional view taken on the line 22 of Fig. 1; and

Fig. 3 is a sectional View taken on the line 3-3 of Fig. 1.

A sound-proof room 9 is constructed of walls 4, 5, 6 and l and a ceiling8 all of which are damped with sound absorbing material 30 such as athick layer of rock wool, felt or other similar material. The walls andceiling are thus damped so as to have a large coefficient of absorptionand provide substantially a sound-dead room. Constructed within thesound-proof room 9 is a sound picture set In comprising side walls I I,l2, l3 and I4 and a ceiling I5 all of which are constructed of wood orany suitable material having a highly reflecting surface. These wallsmay be constructed of movable flats and covered with material decoratedto produce the desired scenic effects. Under certain conditions dampingmaterial may also be applied to one or more of the walls of the set tocontrol acoustic effects. This arrangement therefore provides acomparatively live room I0 within a sound-proof and practically deadroom 9. A live room having a sound absorption coefiicient ofapproximately .2 at a frequency of 1000 cycles per second in a dead roomhaving a sound absorption coefiicient of approximately .8 at a frequencyof 1000 cycles per second has been found to give satisfactory results.

The ceiling l5 of the sound picture set I0 is shown supported from theceiling 8 of the soundproof room 9 by any suitable means such as hangersI6. As shown in Figs. 2 and 3 the ceiling I5 is supported in spacedrelation to the upper edges of the walls II, l2, I3 and I4 providing anopening I! adjacent the ceiling for ventilation and light. Supported onstandards l8 outside of the set I 0 are platforms l9 on which aremounted lamps 20 for lighting the interior of the set I 0 through theopening N. This opening may also be closed with glass or othertransparent material through which the lights may be directed into theset. In the wall II is an opening or doorway 22 outside of which isstationed a picture camera 2| in the room 9. A transmitter pick-up 24connected to any wellknown sound recording system, not shown, may besupported in the opening 22 by a tripod 23 as shown, or within the set.All sounds passing through the opening 22 are absorbed in the room 9.The opening 22 in conjunction with the room 9 therefore acts as anefficient sound sink.

With the arrangement herein described most of the sound from a sourcewithin the set will be reflected a greater number of times than with theusual sound picture set before it reaches the transmitter with theresult that the interference patterns will be less marked and theintensity level will be more uniform for all frequencies and for anyposition of the source or the microphone in the set. With thisconstruction performers are also less restricted in their field ofaction with reference to the microphone on account of the additionalreflecting surfaces. Although the sound picture set is shown as havingfour side walls, the number of walls may be increased.

What is claimed is:

1. The combination of a studio having highly damped walls and asubstantially enclosed sound picture set disposed therein, the walls ofsaid set having a substantially lower sound absorption coeificient thanthe walls of the studio.

2. The combination of a sound studio, the walls of which have soundabsorption coefiicient of substantiallyifi at'a frequency of 1000 cyclesper second and a substantially enclosed sound picture set, the interiorsurface of the walls of which has a sound absorbing coefiicient ofapproximately .2 at a frequency of 1000 cycles per second. r

3. In a sound picture set incombination, a sound damped room, a picturesetslocated with in said room and comprising four side-walls, and aceiling, one of said side walls being proroom, a sound picture setlocated within said sound deadened room and comprising a' plurality ofsound reflecting flats constituting an enclosure for, the action andsound, and a camera and microphone focused upon the sound picture set.-

FRANKLIN L. HUNT.

